OSX should work too. The binaries for OSX and win are never touched as none of the current team has machines to compile bins for that (and the actual game code is in QC which runs on a VM on the engine itself, so the engine binaries don't need to be recompiled). Linux 32 and 64 bins are updated when there is some fix or little feature added to the engine (almost never). We'd like to start hacking more on the engine and extending things (max entity, a bunch of other things, such as "god flare" for suns) someday but will need to learn the magic of making releases for OSX and win before then.